Patricia M Carrascosa MD, Abstract Co-Author: Research support, Koninklijke Philips Electronics NV

Alejandro Deviggiano MD, Abstract Co-Author: Nothing to Disclose

Carlos Capunay MD, Presenter: Nothing to Disclose

Manuel Lewkowicz, Abstract Co-Author: Nothing to Disclose

Jorge Manuel Carrascosa MD, Abstract Co-Author: Nothing to Disclose

Mario Garcia MD, Abstract Co-Author: Research grant, Koninklijke Philips Electronics NV

To show the usefulness of prospective axial-gated CT scans (PAG) in the evaluation of perfusion defects in correlation with digital angiography (DA) coronary stenosis.

Fourty-five patients with suspected CAD were studied with a 64-row PAG-MDCT. One rest scan was done to all patients and a second stress was complemented with pharmacologic stress using 0.56 mg/kg of Dipiridamole in patients with moderate or doubtful stenosis. For the first scan a low heart rate was required (<60bpm). The technical parameters were: 64x 0.625 collimation, 120kV, 150/210 mAs depending on patient’s size. The scan was triggered at the mid-diastolic phase. If the patient did not present CAD or if he presented one or multivessel critical stenosis the study was finished in this phase. DA was done to all patients within 15 days of the MDCT using the conventional Judkins technique. MDCT performed two evaluations: 1) Measurement of CAS (using a 17 segments classification). Stenosis >/= 70% were considered as positive findings. 2) Myocardial perfusion evaluation: Short and long axis were created and a 17 segmental analysis was done. In each segment a qualitative analysis was performed. After the evaluation the segments were correlated with the anatomical division of the main coronary arteries.  

Only 18 of 45 patients performed the second CT scan. There were no complication in the patients studied. Fifty-four vessels were analysed. There were 19 true positive findings, 29 true negative findings, 3 false positives findings and 3 false negative findings. The sensitivity, specificity, positive predictive value and negative predictive value were 86.36% (65.09-97.09), 90.62% (74.98 – 98.02), 86.36% and 90.62% respectively.

Prospective axial-gated CT scans with perfusion scan showed good sensitivity and specificity for the detection of myocardial perfusion defects in cases of significant coronary artery stenosis.

Prospective axial-gated cardiac CT myocardial perfusion evaluation could give functional test to evaluate clinical relevance of coronary stenosis in a two-step study with low effective radiation dose.

Carrascosa, P, Deviggiano, A, Capunay, C, Lewkowicz, M, Carrascosa, J, Garcia, M, Anatomic and Functional Evaluation Using Low-Dose ECG-gated Prospective Cardiac CT.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8011093.html